Single Point Constraints

The interface program places the following comment cards at the start of the constraints section of the NASTRAN input file.

$
$ SINGLE POINT CONSTRAINT CARDS ... 
$

Rigid constraints are defined using the command `PROPERTY BOUNDARY CONSTRAINT'. The user supplies a degree of freedom indicator (eg. 1234) to indicate which degrees of freedom are to be constrained. The names of the degrees of freedom and the degree of freedom macros that may be used are shown in table below.

Degree of freedom name Meaning

1 or X x-translation

2 or Y y-translation

3 or Z z-translation

4 or RX x-rotation

5 or RY y-rotation

6 or RZ z-rotation

XSYMM x-translation, y,z-rotations

YSYMM y-translation, x,z-rotations

ZSYMM z-translation, x,y-rotations

ALL x,y,z-translations, x,y,z-rotations

XASYMM x-rotation, y,z-translations

YASYMM y-rotation, x,z-translations

ZASYMM z-rotation, x,y-translations

ENCASTRE x,y,z-translations, x,y,z-rotations

PINNED x,y,z-translations

NOROTATE x,y,z-rotations

The interface produces a series of SPC cards for all constrained nodes in the model for example:

$   TYPE     SID       G       C       D       G       C       D
SPC            1       1  123456       0       2     456       0
SPC            1       3     456       0       4   13456       0
SPC            1       5     456       0       6     456       0